Chain drive arrangement for internal-combustion engines



Aug. 2, 1949.

JOZIF 2,478,106

J. CHAIN DRIVE ARRANGEMEN OH INTERNAL-COMBUS N EN ES Filed Dec. 1946 atented Aug. 2, 1949 CHAIN DRIVE ARRANGEMENT FOR INTER- NAL-COMBUSTION ENGINES Josef Jozif, Prague, Czechoslovakia, assignor to Zbrojovka Brno, Brunn, Czechoslovakia Application December 26, 1946, Serial No. 718,582 In Czechoslovakia January 3, 1946 4 Claims. 1

The present invention relates to an arrangement of the chain drive of the gearshaft located in the cylinder head of air-cooled internal combustion engines. The main feature of the arrangement according to this invention is that walls forming chambers are cast integrally with the engine casing, cylinder and cylinder head, said chambers forming a continuous channel within the built-up engine casing, cylinder and cylinder head for receiving therein the drive chain. Said channel passes through the cooling ribs in such manner as to be completely surrounded by the cooling ribs on the casing, cylinder and cylinder head.

In the hitherto familiar arrangements of chain drives of the above mentioned type it is usual practice to close the drive chain passage by a special cover. Such arrangement presents, however, the drawback that such cover interrupts the cooling ribs on a rather considerable portion of the periphery of the cylinder respectively cylinder head so that cooling is unsymmetrical. Moreover the oiltight sealing of said cover presents the usual difliculties, since the cover usual- 1 is of a considerable length and fits on points which in the running engine are unevenly heated.

The arrangement according to the present invention eliminates the above mentioned drawbacks and furthermore is more simple in design and of cheaper manufacture, as certain elements as well as machining of the fitting surfaces are dispensed with.

The accompanying drawing shows, by way of example merely, diagrammatically one embodiment of the present invention.

Fig. 1 is a vertical partial section of the engine arranged according to the invention.

Fig. 2 shows a cross section on the line 11-11 in Fig. 1.

Referring to the drawing now, I is the engine casing, 2 the cylinder and 3 the cylinder head. On the crankshaft 4 a gear 5 is keyed in mesh with another gear 6 firmly coupled to the sprocket Wheel l. The chain 8 transmits the motion from the sprocket wheel I to the sprocket wheel 9 keyed on the gearshaft I0. Inside the casing l a chamher it is cast for the chain passage, and similariy a chamber I2 in cylinder 2 and a chamber 23 in cylinder head 3. Said chambers H, l2 and it form in the built-up casing, cylinder and cylinder head a continuous channel wherethrough runs the drive chain 8. The cooling ribs l4 surround the drive chain passage as well as the cylinder 2 respectively casing or head, as can be clearly seen in Fig. 2. The engine casing, cylinder and sprocket mounted on said casing and operatively connected with said crankshaft, said casing, cylinder and cylinder head being each provided with a chamber cast therein, all of said chambers being in alinement with each other to form a straight continuous channel, and an endless drive: chain passing over said two sprockets and extending through said channel.

2. In an air-cooled internal combustion engine,

an engine casing, a crankshaft rotatably supported therein, a cylinder mounted on said casing, a cylinder head mounted on said cylinder, a gear shaft having a sprocket thereon mounted on said cylinder head, a gear on said crankshaft, another gear rotatably mounted on said engine casing and meshing with said first named gear, another sprocket fixed to said other gear to rotate with the same, said casing, cylinder and cylinder head being each provided with a chamber cast therein, all of said chambers being in alinement with each other to form a straight continuous channel, and an endless drive chain passing over said two sprockets and extending through said channel.

3. In an air-cooled internal combustion engine, an engine casing, a crankshaft rotatably supported therein, a cylinder mounted on said casing, a cylinder head mounted on said cylinder, a gear shaft having a sprocket thereon mounted on said cylinder head, means for driving another sprocket mounted on said casing and operatively connected with said crankshaft, said casing, cylinder and cylinder head being each provided with a chamber cast therein and with cooling ribs cast thereon, all of said chambers being in alinement with each other and being arranged within the wall portions carrying said cooling ribs to form a straight continuous channel, and an endless drive chain passing over said two sprockets and extending through said channel.

4. In an air-cooled internal combustion engine, an engine casing, a crankshaft rotatably supported therein, a cylinder mounted on said casing, a cylinder head mounted on said cylinder, a gear shaft having a sprocket thereon mounted REFERENCES CITED The following referemces are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,495,883 Williams Feb. 7, 1922 1,837,564 McCaleb Dec. 22, 1931 

